Setting up HR WDH

MarqPaj · Member

Setting up HR WDH

Delta18 · Guru

Sounds like you are going ok Marg.

Theoretically if you measure alongside your rear wheel from the ground to the underside of the top of the mudgaurd prior to hooking up the van, then again with the van connected.

Fitting the hitch should bring the second measure back to the first.

As to mirrors, if your budget runs to it get a set of Clearview mirrors. You will never look back..(ha ha) www.clearview.com.au

Mike196 · Senior Member

Really nice to see someone post that understands the necessity to change settings to get the required outcome, and as you have found out one link on the chains does make a difference, well done.

Regards,

TAJ · Senior Member

we do different things and they work i measure front wheel

arch to ground told years ago by hay/reece agent

TAJ

deverall11 · Guru

When we had a Paj, I ended fitting airbags in the back. This helped to stop a lot of yaw and did not adversely affect the WDH. And when not towing, let most of the air out of the bags and you are back to a nice supple ride.
Larry

brickies · Guru

I would contact Hayman Reece and you will find they are very helpful . When I had the car I was told to take the measure from front wheel arch , When I got the Prado had a talk to them and was told to message front and back arch to kept the tug level when loaded with the caravan hitch ,They may have different advice for your tug but I have found the advice they gave me was perfect .

keiron · Senior Member

I am using a hitch I purchased in Victoria. It has 30mm diameter bars and an adjustable hitch.

I drive a Patrol, and when I adjust the hitch to get the van coupling at a respectable height, I am unable to open the rear doors on my tug.

To be able to open the doors I have needed to lower the hitch, and with the WDH bars connected my coupling is only about 150mm off the ground.

Am doing something wrong, and what do other Patrol drivers do?

MarqPaj · Member

Cheers for the responses. Very helpful and reassuring in these early days of Newbiedom. Measure and measure again. Makes for a good point of reference and adjustment for the particular ride with the particular weight. Care obviously needed to check out the tow ball weight to keep within the range. As for handling, getting the nose down made a noticeable difference to the front end and where the rubber hits the road, quite a noticeable difference infact. Surprising what one chain link on the WDH correlates to!

MarqPaj · Member

Not sure on the Patrol issue Keiron. Perhaps admin might prompt your post as a new thread. The Paj has the rear door/spare tyre problem as well. I just contacted Mitsubishi today and will be picking up a lift kit for the spare wheel on Wednesday. No more concerns over having to unhitch to get the gear out of the back for flat tyres etc.

PeterD · Guru

The way to set up your WDH is to follow the HR instruction sheet. - http://www.southcoasttrailers.com.au/picts/WDH_Installation_Instructions.pdf This sheet may be for a slightly different WDH style but the principles remain the same.

When measuring the wheel arches it is the front arch that is the important measurement point. The front suspension should come down nearly to the van unhitched height. This will mean that the weight removed by the weight on the ball is nearly restored. It is better to under compensate the weight loss than over compensate for it.

If you are measuring the rear axle height as the principal measurement you can lead to a dangerous set-up. If the bars are tensioned so as to lift the rear wheel arch to the pre hitch-up height this means that the rear axle is not carrying any of the ball load. The ball load is being distributed to the tugs front axle and the vans axle group. This in turn will change the tugs handling from a desirable under-steer to an undesirable over-steer characteristic. You do not want your van pushing the rear axle around when the tug is over-steering. With the van on behind you want the extra friction between the tyres and the road that the extra loading on the rear axle gives you.

The following diagram shows how the ball weight is distributed both with and without WDH after the van has been hitched up. The weights were taken during an actual HR demonstration at a Melbourne caravan many years ago. Do some figuring with pencil and paper to see the increase and decrease in the axle weights (adding the two van axles together.) As I said, this is a very old demo, the front axle has been over compensated. Since then the views on how things should be done have changed a little.

HR WDH display.jpg

-- Edited by PeterD on Tuesday 6th of January 2015 05:21:18 PM

Dunmowin · Guru

keiron wrote:
I am using a hitch I purchased in Victoria. It has 30mm diameter bars and an adjustable hitch.
I drive a Patrol, and when I adjust the hitch to get the van coupling at a respectable height, I am unable to open the rear doors on my tug.
To be able to open the doors I have needed to lower the hitch, and with the WDH bars connected my coupling is only about 150mm off the ground.
Am doing something wrong, and what do other Patrol drivers do?

We have a Nissan Patrol, towing a 3.5t Kedron. We have a Hitchmaster DO35, as all other hitches created the same issue.

MarqPaj · Member

Just got back from a 2500 round trip across NSW. The Paj with Galaxy Odyssey and HR WDH performed well. No issues to report. No over heating of the transmission or probs with the WDH set up. However, I will be following up on the recs as per your post Peter. Getting the balance right between front and back with any given load is worth the fine tuning. I am particularly interested in what it might mean should too much weight be distributed to the front and insufficient to the rear.

PeterD · Guru

Michel, When you check your WDH settings it's the front wheel arch that is the important measurement. Measure the height of the front wheel arch to the ground and note the measurement. After you hitch the van that measurement will rise due to the extra weight on the hitch removing weight from the front suspension and wheels. You then tension the bars so that increased measurement is reduced to as close as you can get it to the first measurement. If you make that height less than the original it means you are putting too much weight on the front tyres and in return you have too little load on the rear tyres.